1. Field of the Invention
The invention relates generally to apparatus for washing parts to remove greases, oils and dirt, the invention particularly relating to low pressure apparatus which recirculates a water detergent solution at a relatively high temperature to spray the solution onto grime-laden parts moving on a perimeter-supported turntable mounted for rotation within the apparatus.
2. Description of the Prior Art
Apparatus intended for cleaning oils, greases and similar debris from parts such as parts removed from a vehicle engine or body when repairing the vehicle have long been known in the art. Although such apparatus are particularly useful in the washing of automotive parts, it is to be understood that parts of virtually any type which can become soiled especially by greases, oils and debris which mixes with such greases and oils can be washed with parts washing apparatus of widely varying description according to the art. Such prior apparatus typically use either an organic solvent as the washing liquid or a mixture of a detergent with water which forms an aqueous cleaning solution. Those parts washing apparatus utilizing organic solvents have become unusable in many states and municipalities due to environmental problems including disposing of the organic solvent itself Further, since such solvent washers cannot heat the solvent used for parts cleaning, the solvent must be sprayed at high pressures which can result in forcing debris of certain types into crevices and the like in certain types of parts with little prospect of removing such debris from the part. Parts washers are known which embody low pressure spraying of aqueous detergent solutions onto the parts to be cleaned, the parts being cleaned by a xe2x80x9cfloodingxe2x80x9d process rather than by a xe2x80x9cblastingxe2x80x9d process.
While turntables have previously been used for mounting parts to be cleaned for rotary movement relative to spraying nozzles within a parts washer, the prior art has not envisioned the mounting of such a turntable about its periphery and supported by structure associated with the periphery of a conical solution reservoir, roller bearings mounted to the periphery of the conical reservoir engaging peripheral portions of the turntable to permit random location of parts, including heavy parts, on the turntable without concern for unbalancing of the turntable and thus tilting. Low pressure parts washers of the prior art typically require heating of the cleaning solution, a requirement which takes a substantial amount of time and energy. The present parts washing apparatus utilizes an extremely efficient heating element and perforated tube arrangement, the tube acting as a radiator with heated solution moving through the perforations into the conical solution tank. The heated solution is continuously recirculated and is brought in contact in each circulation cycle with heating elements disposed internally of the perforated tube. The heating elements are thus maintained in a clean condition.
Examples of the prior art include the parts washer disclosed in U.S. Pat. No. 5,640,981 by Niemela et al, this parts washer lacking the energy efficient heating element and radiator tube arrangement of the invention. Minkin, in U.S. Pat. No. 4,143,669, describes a parts washer having a higher powered liquid spray than does the present invention, such higher pressure sprays being used with organic solvents. In U.S. Pat. No. 5,385,159, Mead describes a parts washer having an upper tank open at the top with a sloped bottom portion which facilitates settling of sludge.
Accordingly, a need exists in the art for a parts washer which effectively and efficiently removes dirt in the form of caked greases, oils and debris and which uses a recirculating water and detergent solution sprayed onto soiled parts at low pressures and which is capable of cleaning soiled oily and greasy parts within a short period of exposure to the cleaning solution. The art has also suffered a long felt need for an aqueous cleaning solution parts washing apparatus whereby the solution may be heated to a desirable cleaning temperature rapidly and with energy efficiency.
The invention provides a low pressure hot water parts washing apparatus which recirculates an aqueous detergent solution between a conical solution reservoir disposed in a lowermost portion of the apparatus to a spray manifold located within an uppermost spray chamber wherein the hot solution is sprayed onto parts which are to be cleaned. The parts are placed on a perforated turntable which rotates at about three revolutions per minute relative to the spray manifold which is fixed in place within the spray chamber. The turntable is supported about its full periphery by roller bearings which are mounted about the periphery of the conical solution reservoir, it being possible to place heavy parts which are to be washed at any location of the turntable without concern for tilting of the turntable due to imbalance brought about by non-judicious placement of parts on the turntable. The turntable is driven through a sprocket and chain drive arrangement by an electric motor disposed externally of the spray chamber, the drive arrangement constituting a positive drive which avoids slippage as can occur in friction drive arrangements.
The spray chamber and the conical solution reservoir communicate with each other but are separated by means of removable perforated plate elements which effectively act as filters to prevent solid debris from collecting in the conical reservoir.
Heating elements effectively and efficiently heat the solution within the conical solution reservoir and are disposed within a tubular perforated radiator which protects the heating elements and which assists in efficient heating of the solution. Cleaning solution in its normal recirculating path through the apparatus moves from the reservoir through holes in the tubular radiator to pass by the heating elements and thus clean the heating elements on a continuous basis during washing operation. Heating element function and life are thus improved and increased by this particular cleaning solution recirculation arrangement.
A programmable control unit is preferably used to control the time of operation of the apparatus by turning the apparatus on and off at preselected times without the need for intervention after programming. An automatic oil skimmer is also operated by the controls, the controls further monitoring water temperature and water level. Still further, the controls monitor the lifecycles of internal components of the apparatus and indicate over time the time of operation of the apparatus. A sealing door carried by rollers movable on a track formed integrally with a lower portion of the apparatus is easily closed and opened by a user, a proximity switch being employed to indicate whether the door is open, operation of the apparatus being discontinued as long as the door is open.
The controls also operate a wastewater evaporation function on the command of a user, the temperature of the solution being increased on command to evaporate water from the cleaning solution, the residue of the solution simply being removed from the apparatus after water evaporation. The controls also operate automatic water fill functions and control a low-water shutoff sensor. A removable parts tree can be provided within the interior of the spray chamber for mounting of small parts during a cleaning cycle. Removable castors can be employed for rolling of the apparatus and the castors can be removed to open up channels at the lowermost portion of the apparatus which receive lift elements of a fork lift for efficient movement of the apparatus.
Accordingly, it is a primary object of the present invention to provide a low pressure, hot water parts washing apparatus which recirculates a heated water/detergent solution within the apparatus and sprays the solution onto oily and dirt-laden parts moving relative to a perforated spray manifold on a rotary turntable, the aqueous solution being sprayed at low pressure through perforations in the manifold at low pressure.
Another object of the invention is to provide a parts washing apparatus operable at low pressure wherein parts mounted on a rotary turntable are cleaned by a low pressure spray of aqueous cleaning solution, the turntable being mounted for rotation by roller bearings fixedly mounted about an upper periphery of a conical solution reservoir within which the cleaning solution is heated and to which the cleaning solution is drained after spraying.
It is yet another object of the invention to provide a parts washing apparatus which recirculates a heated water/detergent solution into contact with parts which are to be cleaned and a solution heating chamber within which the solution is heated by heating elements disposed within a perforated tube which acts as a radiator to facilitate heating of the solution and which allows cleaning solution to be drawn into the interior of the tube and into contacting relationship with the heating elements so that the heating elements are continuously subjected to the cleaning action of the recirculated cleaning solution.
Further objects and advantages of the invention will become more readily apparent in light of the following detailed description of the preferred embodiments.